survival instinct

noun2

1. •
   Any of various unlearned, unthinking responses that serve to preserve one's life or make it difficult to risk one's life.

   • The prey drive, or chase instinct, is another survival instinct. — 1993
2. •
   The will to live and thrive.

   • The better approach is to show them that their survival instinct is tied to cooperation, not turf. — 2000